Conventional condensation-curable room temperature fast-curing organopolysiloxane compositions include one part-type compositions in which amount of the crosslinking agent has been reduced to the minimum level to thereby increase the crosslinking speed, and the two part-type compositions in which the crosslinking agent and the curing agent have been separately packaged. However, the one part-type composition does not really have a fast curability since it only exhibits high curing speed on its surface, and a considerable time is required for the in depth curing. The two part-type composition, on the other hand, has the drawback of poor handling convenience since the two parts cannot be mixed at a ratio of 1:1, and it is not adapted for use in an automatic mixer despite its relatively high in depth curability. Furthermore, in order to accomplish complete curing to the full depth, a strict control in the amount of the crosslinking agent and the curing agent added, or alternatively, an addition of water as an in depth curing agent was necessary. In the meanwhile, an addition curable organopolysiloxane composition requires a heated furnace for its curing although it has improved workability since the two parts can be mixed at a ratio of 1:1. The addition curable organopolysiloxane composition also has the drawback that the working conditions are limited since the curing catalyst is poisoned in the presence of an addition poison.
Generation of water in the composition system is effective in solving such problems. Japanese Patent No. 2811134 (Patent Document 1) proposes use of the water generated as a side product in the course of ketimine formation between an organic compound having at least one C═O group in its molecule and an organic compound having at least one NH2 group in its molecule for the depth curing agent. Japanese Patent No. 2841155 (Patent Document 2) proposes use of water generated as a side product in the course of ketimine formation between the ketone compound generated from an alkenoxysilane and a primary amine compound for the in depth curing agent. Japanese Patent No. 3121188 (Patent Document 3) proposes use of water generated as a side product in the course of Michael addition between a β keto ester compound and an organic compound having at least one NH2 group in one molecule for the depth curing agent. However, in order to supply the water at an amount sufficient for the crosslinking reaction, volatile components such as the organic compound having C═O group and the organic compound having NH2 group, the alkenoxysilane and the primary amine compound, the β keto ester and the organic compound having NH2 group should be added at a large amount. Use of the methods requiring such addition of volatile components at a large amount will be gradually limited in consideration of the increasingly severe regulations of environmental load substances such as sick house regulations and VOC regulations.
Japanese Patent Application Laid-Open No. 2002-338811 (Patent Document 4) proposes use of the water generated in the course of neutralization between a carboxylic acid generated by hydrolysis of a hydrolyzable silane having at least two acyloxy groups in its molecule or its partial hydrolysate and an inorganic filler for the in depth curing agent. However, such curable composition generating a carboxylic acid which generates a carboxylic acid has extremely limited applications because of the metal corrosion problem.
Japanese Patent Application Laid-Open No. 2002-12767 (Patent Document 5) proposes direct supply of the moisture by incorporating a moisture-containing wet silica in the composition, and use of the thus supplied moisture for the in depth curing agent. However, control of the curing reaction is difficult when the moisture is directly supplied, and workability is hardly realized.
Japanese Patent Application Laid-Open No. 2000-129130 corresponding to U.S. Pat. No. 5,969,075 (Patent Document 6) discloses a room temperature-curable organopolysiloxane composition comprising an amino group-containing silane and 1-methylvinyloxy group-containing silane, and having a good flowability. However, the amino group-containing silane used in the composition does not form a compound having —NH2 group when hydrolyzed. This does not make the composition fast-curing.